For example my Gateway E-1400 has Intel 82557/8/9/0/1 Ethernet Pro 100 (rev 08) network card which does not work without firmware-linux installed. If you boot FoxyRoxy and you don't have internet connection type ifconfig command. The normal output should be similar to this one if you have only one network card:

If this is the case download the filmware-linux packages (from another OS) from the links above. One of the packages is a dependency of the other one. Then boot FoxyRoxy and install them with this command:

After reboot you should have working internet.Anyway just in case it doesn't happen and you still don't have internet connection, this is the way to setup your network from command line (the IP, Netmask, Gateway and DNS servers for you most likely will be different):